"Truck tractors" refers to the front part of a truck without a trailer attached. It is specifically designed to pull or tow heavy loads, such as large trailers or shipping containers. Full definition
Now there are indeed stunts in the movie that involve a lot of cars and a semi truck tractor trailer, but that's not until the finale. (fatmovieguy.com)
NHTSA has been conducting extensive research on stability control systems for truck tractors and large buses since 2006. (iihs.org)
Based on the agency's own testing and the results from industry - provided test data, two stability performance tests were proposed to evaluate ESC systems on truck tractors and large buses — the SIS test and the SWD test. (federalregister.gov)